TS, attend the arraignment with or without your lawyer. if your case will be called, you may tell the hearing judge that you have no lawyer yet. thus for purposes of arraignment, the court (on that day) will assign a lawyer to assist you in entering your plea. after such, that said lawyer will be dispensed of his/her duty on you by the court also (you don't have to pay this lawyer.).
After entering your plea, your hearing judge will order you to attend the mediation. by then hopefully, you can find a lawyer of choice already.